As known, in modern electrical systems designed for industrial use, safety devices are provided against failure or anomaly phenomena that may impair the correct system operation. In fact, without such safety devices, any anomalies and failures may damage both the utility equipment or “loads” present in the system and the same breakers, which connect/disconnect such loads from the system. In addition, hazard conditions may occur for the people that use such utility equipment.
An example of safety device for industrial electrical systems generally comprises a fuse associated with a thermal breaker. The thermal breaker is capable of disconnecting the load from a mains supply line of the system in case of overcurrent due to overload, while the fuse trips to protect the electrical system from short-circuit currents.
A drawback of such known safety device that uses the fuse is related to the need of resetting the safety following the occurrence of the short-circuit in the system, in particular by removing the faulty fuse to replace it with a new one. Such operation for replacing the fuse is often a burdensome manual activity that requires the assistance of a skilled operator.
Moreover, the breaker of the safety device with fuse is not exempt from damages that may be caused by transient phenomena that occur with short-circuits.